Recent Advances on Synthesis of CoCO3 with Controlled Morphologies.

Cobalt carbonates and derivatives represent most promising cost-effective materials for energy storage, conversion and upgrading. Morphology determines the performances, as size, shape and electronic configuration are key factors for tunable properties in the area of batteries, catalysis, magnetics and plasmonics. However, there is lack of insights in literature on morphological control of cobalt carbonates during hydrothermal and solvothermal conditions. Therefore, this review provides detailed discussion on synthesis, formation mechanism and morphological control of nanosheets, wires, spheres and cubes of cobalt carbonates. Furthermore, the influence of experimental conditions and plausible mechanism which govern the growing processes were further discussed in details. The outcome of this short review will offer insights into rational design of inexpensive metal carbonates for numerous other energy and environment applications.

Hydrophobic Biodegradable Hyperbranched Copolymers with Excellent Marine Diatom Resistance.

As the utilization of degradable polymer coatings increased, the accompanying trade-off between good degradability and high-efficiency antidiatom adhesion due to their hydrophobic nature remains unresolved. The study presents a new hydrophobic surface-fragmenting coating consisting of degradable hyperbranched polymers (hereafter denoted as h-LLAx) synthesized by reversible complexation-mediated copolymerization with isobornyl acrylate (IBOA) and divinyl-functional oligomeric poly(l-lactide) (OLLA-V2), both derived from biomass, that exhibited superior resistance (∼0 cell mm-2) to marine diatom Navicula incerta (N. incerta) attachment with higher OLLA content. The combined impact of the microscale hollow semisphere micelles that self-assembled degradable hyperbranched copolymers and hydrolysis-driven self-renewable surfaces following immersion in seawater may account for the remarkable resistance of h-LLAx coatings against N. incerta. Detailed investigations were conducted across multiple perspectives, from hydrolytic degradation to broad-spectrum antibacterial attachment to ecotoxicity assessment. The excellent features of high resistance to marine diatoms and bacterial attachment, degradability, and environmental friendliness make the as-prepared h-LLAx coatings widely sought after for antifouling coating applications.

Adsorption and Reduction of Cr(VI) Together with Cr(III) Sequestration by Polyaniline Confined in Pores of Polystyrene Beads.

The simultaneous reduction and sequestration of Cr(VI) from wastewater is desirable as a cost-effective and environmentally friendly approach. In this study, we execute a one-step facile synthesis strategy on polyaniline (PANI) composites based on aniline adsorption and polymerization on pores of millimeter-scale polystyrene balls (PANI@PS). The well-defined PANI@PS increased the removal capacity of Cr(VI) by 5.4 times, going from 43.6 (bulky PANI) to 233.7 mg g-1 near neutral pH (6.0) instead of the pH 1-3 documented in other reports, which was higher than that of many reported adsorbents due to its porous structure, numerous interaction sites, and confinement effects in the polymer. Most importantly, PANI@PS could efficiently sequester positive Cr(III) after reducing Cr(VI) to Cr(III) due to its negative surface created by confinement effects confined to the nanopores of PS. Conversely, positively charged bulky PANI repelled electrostatically positive Cr(III); thus, additional precipitation or adsorption treatments were needed in practical applications. Moreover, a coating of PANI can protect PS, as a substrate and a composite, from irreversible damage due to the strong oxidation capacity of Cr(VI), which is another major concern in adsorbing strong oxidants using polymers. A novel strategy to regenerate the exhausted PANI@PS was efficiently executed based on the electrochemical redox reversibility of PANI. Finally, the comprehensive adsorption/reduction/sequestration of Cr on PANI@PS was elucidated in detail.

Optimization of sulfate reduction and methanogenesis via phase separation in a two-phase internal circulation reactor for the treatment of high-sulfate organic wastewater.

To enhance the performance of the internal circulation (IC) reactor when treating high-sulfate organic wastewater, a laboratory-scale two-phase IC reactor with distinct phase separation capabilities was designed, and the sulfate reduction and methanogenesis processes were optimized by segregating the reactor into two specialized reaction zones. The results demonstrated that the first and second reaction areas of the two-phase IC reactor could be maintained at 4.5-6.0 and 7.5-8.5, respectively, turning them into the specialized phase for sulfate reduction and methanogenesis. Through phase separation, the two-phase IC reactor achieved a COD degradation and sulfate reduction efficiency of more than 80% when the influent sulfate concentration exceeded 5,000 mg/L, which were 32.32% and 16.04% higher than that before phase separation. Functional analyses indicated a greater activity of both the dissimilatory and assimilatory sulfate reduction pathways in the acidogenic phase, largely due to a rise in the relative abundance of the genera Desulfovibrio, Bacteroides, and Lacticaseibacillus, the primary carriers of sulfate reduction functional genes. In contrast, all the acetoclastic, hydrogenotrophic, and methylotrophic methanogenesis pathways were inhibited in the acidogenic phase but thrived in the methanogenic phase, coinciding with shifts in the genus Methanothrix, which harbors the mcrA, mcrB, and mcrG genes essential for the final transformation step of all three methanogenesis pathways.

Oxygen Vacancy Promoted Generation of Monatomic Oxygen Anion over Ni2+ -Doped MgO for Efficient Glycolysis of Waste PET.

Developing efficient and eco-friendly catalysts for selective degradation of waste polyethylene terephthalate (PET) is critical to the circular economy of plastics. Herein, we report the first monatomic oxygen anion (O- )-rich MgO-Ni catalyst based on a combined theoretical and experimental approach, which achieves a bis(hydroxyethyl) terephthalate yield of 93.7 % with no heavy metal residues detected. DFT calculations and electron paramagnetic resonance characterization indicate that Ni2+ doping not only reduces the formation energy of oxygen vacancies, but also enhances local electron density to facilitate the conversion of adsorbed oxygen into O- . O- plays a crucial role in the deprotonation of ethylene glycol (EG) to EG- (exothermic by -0.6 eV with an activation barrier of 0.4 eV), which is proved effective to break the PET chain via nucleophilic attack on carbonyl carbon. This work reveals the potential of alkaline earth metal-based catalysts in efficient PET glycolysis.

Molecular oxygen-assisted in defect-rich ZnO for catalytic depolymerization of polyethylene terephthalate.

Polyethylene terephthalate (PET) is the most produced polyester plastic; its waste has a disruptive impact on the environment and ecosystem. Here, we report a catalytic depolymerization of PET into bis(2-hydroxyethyl) terephthalate (BHET) using molecule oxygen (O2)-assisted in defect-rich ZnO. At air, the PET conversion rate, the BHET yield, and the space-time yield are 3.5, 10.6, and 10.6 times higher than those in nitrogen, respectively. Combining structural characterization with the results of DFT calculations, we conclude that the (100) facet of defect-rich ZnO nanosheets conducive to the formation of reactive oxygen species (∗O2-) and Zn defect, promotes the PET breakage of the ester bond and thus complete the depolymerization processed. This approach demonstrates a sustainable route for PET depolymerization by molecule-assisted defect engineering.

Enhanced denitrification using high-molecular-weight poly(lactic acid) blended with lactide as an effective carbon source.

The utilization of wasted Poly(lactic acid) (PLA) as low-cost carbon sources in solid-phase denitrification is hindered by its low biodegradability, which can be attributed to its high molecular weight. This study presents a new approach by blending high-molecular-weight PLA with a small amount of ʟ-lactide (PLA/LAx) to treat nitrate-contaminated wastewater. The addition of ʟ-lactide enhanced the release of carbon from high-molecular-weight PLA. An impressive denitrification efficiency of 96.7% was achieved, accompanied by extremely low levels of accumulated NO2--N (0.1 mg/L) and NH4+-N (0.4 mg/L). The quantity of ʟ-lactide used significantly impacted the bacterial community structure. A high abundance of the phyla Bacteroidota and Chloroflexi associated with polymer degradation was observed. The most dominant denitrifier was the genus unclassified_f__Rhodocyclaceae belonged to the phylum Proteobacteria. This study demonstrates that blending PLA with just 5 wt% lactide can transform it into a highly effective solid-phase carbon source to eliminate nitrates.

Relationship of widowhood with pulse pressure, fasting blood glucose, and mental health in older adults: a propensity matching score analysis.

Background: Transitioning from marriage to widowhood presents inevitable and significant challenges for many older adults. This study explored the impact of widowhood on a range of mental health outcomes, including pulse pressure and fasting blood glucose levels, among older adults in nursing homes. Methods: This cross-sectional study utilized cluster random sampling to recruit participants, with data analyzed from 388 older Chinese adults. Psychosocial traits were assessed using the Perceived Social Support from Family scale (PSS-Fa) for family support, the Generalized Anxiety Disorder 7-item scale (GAD-7) for anxiety symptoms, and the 9-item Patient Health Questionnaire (PHQ-9) for depressive symptoms and suicidal ideation. Propensity score matching (PSM) was employed to control for confounding factors. A multivariate linear regression analysis was performed to explore the relationship between widowhood, mental health outcomes, pulse pressure, and fasting blood glucose levels. Results: After applying PSM, the sample size was refined to 268 (N = 134 for both married and widowed groups) from the initial 388, excluding 120 unmatched cases. Widowed older adults were found to have notably lower family support (ß = -0.81, p = 0.002), increased depressive symptoms (ß = 1.04, p = 0.043), elevated pulse pressure (ß = 8.90, p < 0.001), and higher fasting blood glucose levels (ß = 3.22, p = 0.027). These associations exhibited greater beta values compared to pre-matching analysis. Conclusion: Our findings revealed that widowed participants had reduced family support, an increased risk of depressive symptoms, heightened pulse pressure, and elevated fasting blood glucose in comparison to their married counterparts. Interventions focusing on social support, mental health, and cardiovascular well-being could be advantageous for this at-risk group.

Fabrication of anion exchanger resin/nano-CdS composite photocatalyst for visible light RhB degradation.

A novel nanocomposite photocatalyst, D201-CdS beads (0.70-0.80 mm in diameter), was fabricated for visible light (λ > 420 nm) photodegradation of Rhodamine B (RhB). Sphalerite CdS nanoparticles (5-15 nm) were distributed within the outer layer of D201 for favorable visible light permeation. Ultraviolet-visible spectral changes of RhB solution indicated that efficient RhB photodegradation was achieved by D201-CdS under visible light irradiation. More attractively, negligible photocorrosion of the hybrid catalyst D201-CdS was demonstrated by the constant photodegradation efficiency and negligible CdS leaching during five-cycle batch runs. Besides the higher stability, D201-CdS is superior to CdS in terms of separation. The used nanocomposite can be readily separated from solutions by a simple filtration while a high speed centrifugation is needed for the separation of CdS. The above results suggested that the resultant D201-CdS nanocomposite catalyst is promising for practical application in environmental remediation.

Characterization of hydrophobic hypercrosslinked polymer as an adsorbent for removal of chlorinated volatile organic compounds.

A hydrophobic hypercrosslinked polymer with poly (4-tert-butylstyrene-styrene-divinylbenzene) matrix (LC-1) was prepared as adsorbent for the removal of volatile organic compounds from gas streams. The content of oxygen-containing functional groups of LC-1 was about one-fourth that of commercial hypercrosslinked polymeric adsorbent (NDA-201). The results of the water vapor adsorption experiment indicated that LC-1 had a more hydrophobic surface than NDA-201. Three chlorinated volatile organic compounds (trichloroethylene, trichloromethane, and 1, 2-dichloroethane) were used to investigate the adsorption characteristics of LC-1 under dry and humid conditions. Equilibrium adsorption data in dry streams showed that LC-1 had good adsorption abilities for three chlorinated VOCs due to its abundant micropore structure. Moreover, the presence of water vapor in the gas stream had negligible effect on breakthrough time of three chlorinated VOCs adsorption onto LC-1 when values of relative humidity were equal to or below 50%; the breakthrough time of three chlorinated VOCs decreased less than 11% even if the relative humidity was 90%. Taken together, it is expected that LC-1 would be a promising adsorbent for the removal of VOCs vapor from the humid gas streams.

PLA-based core-shell structure stereocomplexed nanoparticles with enhanced loading and release profile of paclitaxel.

Purpose: In the present study, to achieve high paclitaxel (PTX) loading in a conjugated drug delivery system with minimal long-term side effects, we formulated a novel degradable stereocomplexed micelle-like particle with a core-shell structure. Materials and methods: In this system, methoxy polyethylene glycol (MPEG) acted as the hydrophilic shell, and the stereocomplex of polylactic acid with PTX (SCPLA-PTX) acted as the hydrophobic core. The MPEG-SCPLA-PTX micelle-like particles were synthesized via the self-assembly of a MPEG-poly L-lactic acid (PLLA) copolymer with a PTX-poly D-lactic acid-PTX copolymer. The resultant copolymers and their intermediates were characterized using 1H nuclear magnetic resonance and GPC. Micelle-like particles with different molecular weight ratios of MPEG and PLLA were synthesized to demonstrate the functions of both components. Results: PTX loading into MPEG2000Da-PLLA6000Da particles reached as high as 20.11%. At 216 h, the cumulative release from MPEG5000Da-PLLA6000Da, MPEG2000Da-PLLA6000Da, and MPEG5000Da-PLLA22000Da particles were 51.5%, 37.7%, and 52.0%, respectively. Conclusions: According to the cell uptake experiments, inhibition of tumor cell growth was satisfactory, indicating that the stereocomplexed particles developed in the present study can be employed as a promising nanocarrier for PTX delivery.

Oriented Assembly of Anisotropic Nanosheets into Ultrathin Flowerlike Superstructures for Energy Storage.

The hierarchical ultrathin nanostructures are excellent electrode materials for supercapacitors because of their large surface area and their ability to promote ion and electron transport. Herein, we investigated nine l-amino acids (LAs) as inductive agents to synthesize a series of CoNi-OH/LAs materials for energy storage. With the different amino acids, the assembled CoNi-OH/LAs form a lamellar, flower-shaped, and bulk structure. Among all materials, the ultrathin flowerlike CoNi2-OH/l-asparagine (CoNi2-OH/l-Asn) exhibits an excellent specific capacity of 405.4 mAh g-1 (2608 F g-1) and a 100% retention rate after 3000 cycles. We also assembled asymmetrical supercapacitor CoNi2-OH/l-Asn//N-rGO devices, which demonstrated an energy density of 64.9 Wh kg-1 at 799.9 W kg-1 and superlong cycling stability (82.4% at 10 A g-1) over 5000 cycles.

Removal of model dyes on charged UF membranes: Experiment and simulation.

Charged ultrafiltration (UF) membranes can repel electrically charged molecules that are smaller than the size of the membrane pores and display high rejection of solutes, high flux, and low operation pressures compared to uncharged UF, nanofiltration (NF) and reverse osmosis (RO). Here, a charged UF membrane composite (PANI/PVDF) was prepared and regulated via electrochemically reversible control in portions of amine/imine functional groups of PANI. As a result, the permeability and rejection ratios of CR2- on charged PANI/PVDF, with PVDF as a control, increased from 19.6 to a maximum of 183.3 L m-2 h-1 bar-1 and from 3.4% to 74%, which expands the trade-off confine benefited from surface potential change from -12.21 mV to -25.26 mV, furtherly, the rejection ratio of CR2- on PANI/PVDF reached up to 93% via the electrochemical regulation. Finally, a fixed-charge model was built that well describes the steric and electric repulsion effects on membrane performance and the important roles of the electrochemically controllable surface charge. Moreover, the contour map of rejection ratios containing the ratio of molecular size vs the average pore size of the membrane (r/R = 0.2-1.0) and the zeta potential (-10 to -60 mV) were taken into account, which can be used to visually understand the rejection performance of membranes. This model is also appropriate for varying molecular sizes and for molecules with different charges. Our work opens a new horizon for the design of electrochemically controllable charged membranes to remove charged compounds.

Removal of endocrine disrupting chemicals from aqueous phase using spherical microporous carbon prepared from waste polymeric exchanger.

A spherical microporous carbon adsorbent (CR-1), which was developed by carbonization and activation of the waste polysulfonated cation-exchanger, was used to remove Dimethyl phthalate (DMP) and 2, 4-dichlorophenol (2, 4-DCP) as the model compounds of EDCs from the aqueous solution. Four adsorption isotherm models, Langmuir, Freundlich, Toth and Polanyi-Dubinin-Manes equations were tested to correlate the experimental data, Toth and Polanyi-Dubinin-Manes isotherms models provided the best correlation. The Henry's law constants calculated from Toth equation were found to be 705.957 and 6,724.713 L g(-1) for 2, 4-DCP and DMP at 298 K, respectively, and the larger exponents n of the Freundlich model were 9.011 and 9.93 for 2, 4-DCP and DMP at 298 K, respectively. The values of Henry's law constants and exponent n of the Freundlich suggested that CR-1 was an effective adsorbent for removal of low concentrations of DMP and 2, 4-DCP from aqueous solution. Moreover, the adsorption kinetics results showed that adsorption of 2, 4-DCP and DMP on CR-1 was a pseudo-second-order process controlled by intra-particle diffusion and that adsorption uptake reached quickly half of equilibrium capacities within 20 min.

Polanyi-based models for the adsorption of naphthalene from aqueous solutions onto nonpolar polymeric adsorbents.

In this research, naphthalene was adopted as the representative model compound of PAHs, and static adsorption of naphthalene from aqueous solution onto three commercial polymeric adsorbents with different pore structure was investigated. Nonlinear isotherms models, i.e., Freundlich, Langmuir, and Polanyi-Dubinin-Manes (PDM) models were tested to fit experimental data, and the experimental data were found to fit well by the PDM model. Through both isotherm modeling and constructing "characteristic curve," Polanyi theory was useful to describe the adsorption process of naphthalene by polymeric adsorbents, providing evidence that a micropore filling phenomenon was involved during the adsorption process. In addition, a good linear correlation was obtained between the naphthalene adsorption capacities and the micropore volume of adsorbents (Vmicro), whereas no linear relationship was found between the naphthalene adsorption capacities and the specific surface area of adsorbents. Based on the PDM model, the micropore volumes of adsorbents was introduced to normalize the equilibrium adsorbed volume (qv), plots of qv/V(micro) vs adsorption potential density for naphthalene on three different polymeric adsorbents were collapsed to a single correlation curve, which would be of great benefit to predict the adsorption capacity of adsorbent for the purpose of adsorption engineering design.

Biotreatment of p-nitrophenol and nitrobenzene in mixed wastewater through selective bioaugmentation.

This work combined selective adsorption and bioaugmentation to treat mixed wastewater of nitrobenzene and p-nitrophenol. The mixed wastewater of nitrobenzene (217 mg/L) and p-nitrophenol (500 mg/L) was adjusted its pH to 8 and then passed through the adsorption column at 100 mL/h. In effluent the nitrobenzene concentration was less than 4 mg/L. Without the toxic inhibition of nitrobenzene, p-nitrophenol in effluent could be degraded within 60 h through bioaugmentation. About 23 mg/g of nitrobenzene adsorbed the dry resin HU-05 could be desorbed and degraded through bioaugmentation. During this process the adsorption capacity of the resin HU-05 was recovered partly. The recovered extent was limited by nitrobenzene bioavailability. The performance of the resin HU-05 kept stably in the recycle experiments of 60 days.

Application of the Polanyi potential theory to phthalates adsorption from aqueous solution with hyper-cross-linked polymer resins.

The adsorption equilibria of dimethyl phthalate (DMP) and diethyl phthalate (DEP) on two hyper-cross-linked polymer resins (NDA-99 and NDA-150) in aqueous solution were investigated at 298 K. And a coal-based granular activated carbon (AC-750) was chosen for comparison. All the adsorption equilibrium data of DMP were well fitted by the Polanyi-based isotherm modeling (Polanyi-Manes (PM) equation), and the characteristic curves of the three adsorbents were obtained. It is noteworthy that a reasonably good agreement was obtained between the combined micropore and mesopore volume of adsorbents and the corresponding adsorption volume capacity for phthalates. Compared to the granular activated carbon (AC-750), the greater adsorption performances of the two resins (NDA-99 and NDA-150) were assumed to result from their more abundant micro- and mesopore structure, where phthalates can be intensively adsorbed by pore-filling mechanism. According to the exponent b value of the PM equation, NDA-99 and NDA-150 show the more micro- and mesopore heterogeneity than AC-750. On the other hand, the functional groups on the adsorbent surfaces did not take a notable effect on the adsorption equilibria of phthalates. The theory equilibrium adsorption amounts of DEP, predicted by the specific characteristic curve of each adsorbent, agree well with the experimental ones, respectively. The characteristic curve of hyper-cross-linked polymer resins and its prediction of phthalates adsorption calculated by Polanyi-based isotherm modeling have a potential applicability for field applications.

Adsorption of Pb2+, Zn2+, and Cd2+ from waters by amorphous titanium phosphate.

In the current study, amorphous titanium phosphate (TiP) was prepared as an adsorbent for heavy metals from waters. Uptake of Pb(2+), Zn(2+), and Cd(2+) onto TiP was assayed by batch tests; a polystyrene-sulfonic acid exchanger D-001 was selected for comparison and Ca(2+) was chosen as a competing cation due to its ubiquitous occurrence in waters. The pH-titration curve of TiP implied that uptake of heavy metals onto TiP is essentially an ion-exchange process. Compared to D-001, TiP exhibits more preferable adsorption toward Pb(2+) over Zn(2+) and Cd(2+) even in the presence of Ca(2+) at different levels. FT-IR analysis of the TiP samples laden with heavy metals indicated that the uptake of Zn(2+) and Cd(2+) ions onto TiP is mainly driven by electrostatic interaction, while that of Pb(2+) ions is possibly dependent upon inner-sphere complex formation, except for the electrostatic interaction. Moreover, uptake of heavy metals onto TiP approaches equilibrium quickly and the exhausted TiP particles could be readily regenerated by HCl solution.

Adsorptive removal of phenol from aqueous phase by using a porous acrylic ester polymer.

The removal of phenol from aqueous solution was examined by using a porous acrylic ester polymer (Amberlite XAD-7) as an adsorbent. Favorable phenol adsorption was observed at acidic solution pH and further increase of solution pH results in a marked decrease of adsorption capacity, and the coexisting inorganic salt NaCl exerts positive effect on the adsorption process. Adsorption isotherms of phenol were linearly correlated and found to be well represented by either the Langmuir or Freundlich isotherm model. Thermodynamic parameters such as changes in the enthalpy (DeltaH), entropy (DeltaS) and free energy (DeltaG) indicate that phenol adsorption onto XAD-7 is an exothermic and spontaneous process in nature, and lower ambient temperature results in more favorable adsorption. Kinetic experiments at different initial solute concentrations were investigated and the pseudo-second-order kinetic model was successfully represented the kinetic data. Additionally, the column adsorption result showed that a complete removal of phenol from aqueous phase can be achieved by XAD-7 beads and the exhausted adsorbent was amenable to an entire regeneration by using ethanol as the regenerant. More interestingly, relatively more volume of hot water in place of ethanol can also achieve a similar result for repeated use of the adsorbent.

Adsorption of naphthalene onto the carbon adsorbent from waste ion exchange resin: equilibrium and kinetic characteristics.

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants that can result in serious health problems and genetic defects in humans. In this research, a spherical microporous carbon adsorbent (CR-1) had been obtained by carbonization and activation of the waste polysulfonated cation exchange resin. Naphthalene was adopted as a model compound to examine the adsorption effectiveness for removing PAHs from the aqueous solution by CR-1. Nonlinear isotherms models, i.e., Freundlich, Langmuir, Brunauer-Emmett-Teller and Polanyi-Dubinin-Manes models were tested to fit experimental data. The adsorption equilibrium data of naphthalene on CR-1 was fitted well by the Polanyi-Dubinin-Manes model. Through both isotherm modeling and constructing "characteristic curve", Polanyi theory was useful to describe the adsorption process of naphthalene by CR-1, providing evidence that a micropore filling phenomenon is involved. In addition, among the tested kinetic models in this study (e.g., pseudo-first-order and pseudo-second-order equations), the pseudo-first-order equation successfully predicted the kinetic adsorption process.